In this proposed research, we intend to develop two new techniques which will be used to identify a highly effective robotic rehabilitation strategy. Animal models will be used to address issues that cannot be addressed using human patients. Currently, several robotic stroke rehabilitation techniques are being evaluated to determine their effect on human patients' short and long term recovery performance. Robots, for example, are being attached to patients' limbs and applying force to move them as physical therapists routinely do. Such robotic techniques, however, are simple extensions of what physical therapists are already doing, and the only outcome measurements available are patients' behavioral changes. Robots are currently being used on a limited basis in stroke rehabilitation research because it is not ethical to test a variety of robot force fields or techniques on humans if these fields or techniques have not been proven to have a positive effect on them. Therefore, we believe that evaluating robotic rehabilitation techniques on animal models is crucial. To our knowledge, animal models have never been used to evaluate robotic rehabilitation of stroke. To use animal models, we must develop two new techniques that have not yet been explored. First, we will develop a technique to produce a precise lesion in an animal that simulates a stroke without risking the animal's survival rate. To do this, we will use a non-invasive photochemical technique. Second, we will design, construct, and test a new robot controller technology for animals. We will rehabilitate animals using this new robotic controller which will later be applicable to human rehabilitation techniques. We will combine these techniques to establish the superiority of robot-assisted intervention over non-assisted rehabilitation, explore the optimal training schedules, and identify gene products that are selectively modulated following robotic rehabilitation. The results generated in this project will be used as preliminary results to apply for an R01 grant in which effective robotic force assistance will be investigated to identify the optimal therapeutic solution for robotic rehabilitation. We have no doubt that the experimental results we produce with these techniques will significantly affect the field of rehabilitation.